The present invention is in the technical field of analyte sensors. More particularly, the present invention is in the field of exhaled breath chemical sensors. In preferred form, the present invention is in the field of nitric oxide breath sensors. In other preferred embodiments, the invention provides a method and device for measuring the concentration of ethanol in exhaled breath.
Electronic circuits that utilize organic materials, such as graphene, have been explored for their potential use in electrochemical sensors. The attraction to using such compounds is the ability to chemically modify the organic materials to introduce new functionality by, for example, attaching a receptor molecule that sensitizes the device toward a particular analyte.
Many sensors have been conceived that utilize graphene in transistor or resistive circuits for the purpose of sensing. However, it is only recently that the ability to use graphene in a variable capacitor device was demonstrated. Although a graphene variable capacitor design has some advantages for use in breath diagnostic sensing, the graphene varactor itself may not be selective toward any particular compound and may be compromised in its ability to discriminate between the target analyte and interfering compounds.